Part 1 presents a brief overview of witness intimidation, its various forms, and common characteristics of both victims and perpetrators of such intimidation. Topics addressed include the prevalence of such intimidation and its features, which include physical violence, explicit threats, implicit threats and menacing conduct, emotional manipulation, and intimidation promoted by unethical defense counsel. Victims and witnesses particularly vulnerable to intimidation are victims of domestic violence, witnesses to organized crime or gang-related violence, immigrants, human trafficking victims, child and juvenile victims and witnesses, and victim/witnesses in institutional settings. Part 2 identifies solutions that integrate victim and witness safety into criminal justice systems. A "Conceptual Model" is presented for measuring the prevalence of actual intimidation in any jurisdiction. In addition, it portrays common opportunities for intimidation as well as gaps in victim and witness safety. Ten best practice principles are identified for a jurisdiction to use in assessing and comparing its existing system with best practices. These best practices are drawn from the experiences of the three pilot sites of an initiative to improve the justice system's response to witness intimidation (IWI). Part 3 details six action steps for implementing change, describes a research-informed methodology, and provides tools for beginning the change process. This process includes monitoring, evaluating, and improving victim and witness safety efforts. Appended tools, tables, and additional resources